Steam crushed whole grains

ABSTRACT

A steam crushed whole grain for reducing the wetting time necessary prior to use of a whole grain baking ingredient in a baking application. A whole grain kernel is formed into a whole grain flake with a plurality of exterior fractures. As the flake is formed, the flake is exposed to steam such that an interior starch portion of the flake is heated by penetration of the steam through the fractures. As the interior starch portion is heated, the flake is partially gelatinized within a range of about 15% to about 35%. The partially gelatinized grain is then milled and crushed for use as a baking ingredient. Prior to use, the partially gelatinized whole grain baking ingredient is wetted for a time less than 4 hours as is typically recommended for traditionally processed whole grains.

REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/092,326, filed on Mar. 29, 2005 now U.S. Pat. No. 7,704,541, which isincorporated herein by reference in its entirety, and which claims thebenefit of priority under 35 U.S.C. 119(e)(1) of a provisional patentapplication Ser. No. 60/557,605, filed Mar. 30, 2004, which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The invention relates generally to whole grains for baking, particularlyto methods and processes for processing whole grains for use in a bakingapplication.

BACKGROUND OF THE INVENTION

For centuries, grains have been grown and harvested as one of the mostbasic food staples. Grains including corn, wheat, rye, oats and othersare traditionally ground into flour for use as the main building blockfor making a variety of baked goods including breads, pastas, tortillasand dessert items.

Regardless of the grain type, the individual grain kernels comprise afibrous exterior shell referred to as bran, an interior starch portioncalled the endosperm, and a nutrient-rich core called the germ. Duringmilling of the grain kernels, processes can be used to separate andremove the bran and germ from the endosperm resulting in a refined grainthat is almost pure starch. While refined grains have advantages such asappearance and consistency, health studies have suggested that dietshigh in starches, like those from refined grains, play a role in certainunhealthy conditions such as obesity, heart disease and diabetes amongothers. Conversely, many of these same studies have indicated that theuse of whole grains or grains that contain the entire kernel includingthe bran, endosperm and germ, promote certain health advantages.

One reason suggested for the health advantages associated with wholegrains is that the bran and germ are both the nutrient-rich portions ofthe grain kernel and include concentrated portions of essential vitaminsand nutrients. Further, the fibrous make-up of bran provides anexcellent source of dietary fiber. Studies have shown that diets rich inwhole grains can reduce the risks of heart disease, diabetes and certaincancers. Furthermore, other studies have suggested that individuals whoconsume whole grains tend to eat less and as a consequence, may weighless or lose weight. In addition to the health benefits, the use ofwhole grains, for example in bread, is easily identifiable in the flourand consequently the bread is not a homogenous mixture. Since individualwhole grain pieces are visibly identifiable and texturallydistinguishable by the consumer, the mixture provides the appearance ofa healthier alternative.

While the use of whole grains in baking provides numerous healthbenefits, these same whole grains require time-consuming preparationtechniques to make appealing baked goods. In order to use whole grainsin traditional baked goods, the whole grains must be soaked in water for4-8 hours prior to baking. Otherwise, the whole grains will tend toabsorb the water from the surrounding ingredients during the bakingprocess such that the finished product has “hard” and/or “dry” regionsthat can negatively affect the quality of the baked good. Having to soakwhole grains for extended periods of time (4 hours or more)substantially increases preparation time and reduces the throughput ofthe baked goods.

One approach that has been utilized to avoid the extended soaking timefor whole grains is to instantize the grain during the milling process.Instantizing grain involves the process of heating grain kernels suchthat the internal starch of the endosperm is greater than 75%gelatinized. Gelatinization of starch refers to a process of creatingfractures within the individual starch granules such that water ormoisture has a point of entry and can be absorbed quickly by the starchgranules. An example of an instantized grain is “instant oatmeal” thatimmediately absorbs hot water and takes on a pasty consistency.Typically, the process of instantizing grain consists of exposing grainkernels to an infrared heat source such that the internal moisture,typically at least 13% by weight, of the grain kernels, is quicklyconverted to steam which subsequently bursts or cracks the individualstarch granules. While instant grains can be used to reduce the overallsoak period of whole grains, instant grains suffer from the drawbackthat when exposed to water, the starch granules basically disintegratedue to their high gelatinization and the granules becomeindistinguishable in both appearance and texture to a consumer of thebaked good.

As such, it would be advantageous to have a whole grain product that isidentifiable to the consumer as a whole grain that includes all of thedesirable health characteristics associated with whole grains and can beused in a baked good without the need to subject the whole grain tohours of pre-soak.

SUMMARY OF THE INVENTION

The present invention addresses the aforementioned needs of providing awhole grain product that substantially reduces the soaking time prior tobaking while maintaining the visual and textural characteristicsassociated with whole grain. A crushed whole grain of the invention isrolled to form exterior fractures in the grain kernel. At the same time,the fractured kernel is exposed to steam that gelatinizes a portion ofthe interior starch. By partially gelatinizing the crushed grain, thetime associated with water absorption in the bread dough pre-preparationstage is substantially reduced as compared to traditionally processedwhole grains.

In one embodiment, the invention comprises a process for creating acrushed grain bakery ingredient having increased water absorptioncapabilities.

In another embodiment, the invention comprises a bakery ingredientcomprising visually identifiable crushed whole grain and grain fineswherein both the crushed whole grain and the grain fines are partiallygelatinized prior to incorporation into the bakery ingredient to promoteincreased water absorption.

In another embodiment, the invention comprises an intermediate,partially gelatinized whole grain flake suitable for further processinginto a whole grain bakery ingredient.

The above summary of the various embodiments of the invention is notintended to describe each illustrated embodiment or every implementationof the invention. The figures in the detailed description that followmore particularly exemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments of the inventionin connection with the accompanying drawings, in which:

FIG. 1 is a section view of a whole grain kernel.

FIG. 2 is a process schematic for a process for milling and wetting apartially gelatinized crushed whole grain according to an embodiment ofthe invention.

FIG. 3 is a schematic view of a forming unit used in the processdepicted in FIG. 2.

FIG. 4 is a schematic view of a crushing unit used in the processdepicted in FIG. 2.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION

As illustrated in FIG. 1, a whole grain kernel 100 comprises a hardouter shell 102 called bran, a nutrient-rich core 103 called germ and aninterior starch portion 104 called endosperm. The composition of wholegrain kernel 100 is representative of kernels from grain includingwheat, rye, oats, barley, corn and triticale.

Referring to FIG. 2, there is illustrated a process 105 for milling apartially gelatinized crushed whole grain according to an embodiment ofthe invention. Supply stream 106 consisting of an amount of whole grainkernels 100 is fed to a forming unit 108. Typically, supply stream 106has a supply moisture content of about 11% to about 14% and atemperature of about 220° F., dependent primarily upon harvestingconditions. If the whole grain kernels 100 are harvested with a moisturecontent higher than about 14%, a farmer may use a drying process toreduce the moisture content to about 13%. In some instances, this dryingprocess/can cause the supply stream 106 to be up to 5% gelatinized priorto being fed to forming unit 108.

As shown in FIG. 3, forming unit 108 can comprise a roller unit 110 anda supply of steam 112. In one embodiment illustrated in FIG. 3, rollerunit 110 comprises a first roller 114 and a second roller 116 in aside-by-side orientation separated by a roller gap 118. First roller 114is a smooth roller while second roller 116 is a corrugated roller. Firstroller 114 and second roller 116 rotate in opposed directions, forexample first roller 114 rotates in a clockwise direction and secondroller 116 rotates in a counterclockwise direction as indicated in FIG.3 such that supply stream 106 is drawn through first roller 114 andsecond roller 116. Supply stream 106 is fed into the top of forming unit108 whereby the whole grain kernels 100 drop through roller gap 118.First roller 114 and second roller 116 can be adjustably positioned suchthat roller gap 118 is less than the diameter of the whole grain kernels100 whereby the whole grain kernels 100 are fractured and flattened,creating exterior fractures 120 within the hard outer shell 102. Atsubstantially the same time whole grain kernels 100 are fractured andflattened, whole grain kernels 100 are exposed to steam 112. Steam 112penetrates exterior fractures 120 causing the moisture content withinwhole grain kernels 100 to increase and approach about 20%. Thepenetration of steam 112 causes interior starch portion 104 to heat up.In areas of interior starch portion 104 that reach a temperature ofabout 190° F. to about 210° F., interior starch portion 104 begins theprocess of gelatinization, whereby the individual starch granules thatmake up interior starch portion 104 begin to experience individualstarch fractures. In this example embodiment, whole grain kernels 100are in contact with steam 112 for up to 5 seconds such that about 15% toabout 35% of the individual starch granules that comprise interiorstarch portion 104 are gelatinized.

Referring again to FIG. 3, once whole grain kernels 100 fall throughfirst roller 114 and second roller 116, the grain has been compressed toform a partially gelatinized, whole grain flake 122. In addition toforming whole grain flakes 122, first roller 114 and second roller 116create a small amount (e.g., 20% or less) of grain fines 123 consistinggenerally of ground flour having a particle size less than 45 mesh,i.e., ground flour that passes through a U.S. Standard # 45 screen. Asgrain fines 123 are created, grain fines 123 are also exposed to steam112. Fines 123 comprise ground versions of whole grain flake 122. Withinfines 123, a larger percentage of the interior starch portion 104 isexposed to steam 112 such that a larger percentage of grain fines 123reach the gelatinization temperature of 198° F. As such, a largerpercentage of the individual starch granules, about 50% to about 65% ofthe individual starch granules present within grain fines 123, aregelatinized to form a partially gelatinized grain fine 127.

Once whole grain flakes 122 and partially gelatinized grain fines 127are removed from exposure to steam 112, interior starch portion 104begins to cool such that further gelatinization is avoided. A partiallygelatinized flake stream 124, comprising whole grain flakes 122 andpartially gelatinized grain fines 127, can then be fed to a crushingunit 128, which may include a gravity feed or an air conveyor. As flakestream 124 is transferred to crushing unit 128, whole grain flakes 122and the partially gelatinized grain fines 127 can dry such that flakestream 124 has a moisture content of less than about 20%.

Referring now to FIG. 4, within crushing unit 128, whole grain flakes122 are crushed between a pair of crushing rollers 130 a, 130 b to forma visually identifiable crushed whole grain 132 suitable for use in abaking product. Crushed whole grain 132 meets the size specificationsfor crushed wheat as defined by the United States in Title 21 of theCode of Federal Regulations (21 CFR 137.195). Crushing roller 130 a caninclude crushing points vertically disposed to a crushing gap whilecrushing roller 130 b can include crushing points horizontally disposedto the crushing gap. Due to their already small size, partiallygelatinized grain fines 127 can generally pass through crushing rollers130 a and 130 b without undergoing significant crushing. Visuallyidentifiable, crushed whole grain 132, on the order of about 80% byweight, and partially gelatinized fines 127, on the order of about 20%by weight, combine to form a partially gelatinized, whole grain bakingingredient 134. The partially gelatinized, whole grain baking ingredient134 has a moisture content of about 13% and is subsequently air conveyedto a packaging or distribution location. The partially gelatinized,whole grain baking ingredient 134 includes all of the components ofwhole grain kernel 100 including hard outer shell 102, nutrient richcore 103 and interior starch portion 104, wherein about 15% to about 35%of the individual starch granules within crushed whole grain 132 hasbeen gelatinized while about 50% to about 60% of the individual starchgranules within partially gelatinized grain fines 127 have beengelatinized. The partially gelatinized whole grain baking ingredient 134is now ready for use in any of a variety of baking applications in whichthe use of whole grains is desired.

Referring back to FIG. 2, prior to its use in a baking application,partially gelatinized whole grain baking ingredient 134 is wetted with awater source 136. Unless wetted prior to baking, partially gelatinizedwhole grain ingredient 134 will absorb water from the other bakingcomponents resulting in the formation of dry and/or hard portions withinthe finished baked good. As described previously, the wetting oftraditional crushed whole grains can last for 4 hours or more. However,an embodiment of the invention substantially reduces this pre-soak time.

Example 1

Comparison was conducted between a traditionally processed crushed wholegrain and partially gelatinized whole grain baking ingredient 134resulting from an embodiment of the invention. For comparison, 100 gramsof each grain sample was soaked. For the traditionally processed wholegrain, a 100 gram sample absorbed 90 mL of water within 5 minutes and113 mL of water after soaking for 4 hours. In comparison, a 100 gramsample of partially gelatinized whole grain baking ingredient 134absorbed 113 mL of water within 5 minutes to form a wetted bakingingredient 138. The increased water absorption properties of thepartially gelatinized whole grain baking ingredient 134 appears toresult from the increased ability of the gelatinized starch granules toabsorb water through the fractures in the individual starch granules. Assuch, the use of partially gelatinized whole grain baking ingredient 134of this example embodiment of the invention results in a reduction ofwetting times by about 98%.

By reducing the wetting times, the cost and expense associated withincreased wetting times can be eliminated and the cycle time of thewhole grain baking process is significantly reduced without affectingthe taste and quality of the finished baked product. In addition, theconsumer can identify the baked product as being a whole grain productby visually and texturally identifying the visually identifiable,crushed whole grain 132 within the product.

Although various embodiments of the present invention have beendisclosed here for purposes of illustration, it should be understoodthat a variety of changes, modifications and substitutions may beincorporated without departing from either the spirit or scope of thepresent invention.

1. A method for processing whole grains, the method comprising:fracturing and flattening a hard outer shell of a whole grain kernel toform fractures in the hard outer shell, while at substantially the sametime contacting the whole grain kernel with steam to partiallygelatinize an interior starch portion of the whole grain kernel byraising a temperature of an area of the interior starch portion to atleast about 190° F. wherein the grain kernel is contacted with steam forup to 5 seconds; forming a partially gelatinized steam treated flakefrom the whole grain kernel wherein an interior starch portion of thesteam treated flake has a gelatinization range of about 15% to about35%; and crushing the steam treated flake to form a partiallygelatinized crushed whole grain for use in a baking product, the crushedwhole grain having an interior starch portion with a gelatinizationrange of about 15% to about 35%.
 2. The method of claim 1, whereinforming the steam treated flake comprises rolling the whole grainkernel.
 3. The method of claim 2, wherein rolling the whole grain kernelcomprises rolling with a corrugated roller, wherein the corrugatedroller flattens and fractures the whole grain kernel to form the steamtreated flake.
 4. The method of claim 3, wherein rolling the whole grainkernel generates a plurality of grain fines.
 5. The method of claim 1,wherein the steam treated flake has an internal moisture content lessthan about 20%.
 6. The method of claim 1, wherein the partiallygelatinized crushed whole grain, after being subjected to a watersource, reaches a moisture level of about 90% within about 60 minuteswhile maintaining the gelatinization range of the interior starchportion of the crushed whole grain at about 15% to about 35%.